carp: retire ioctl(2) API

All supported stable branches use netlink(4) API to configure carp(4).
The deleted code also has kernel stack leak vulnerability, that requires
extra effort to fix.

Reviewed by:		pouria, kp
Differential Revision:	https://reviews.freebsd.org/D55804

Author: glebius

sbin/ifconfig/carp.c

@@ -156,8 +156,13 @@ setcarp_callback(if_ctx *ctx, void *arg __unused)
 	if (carpr_vrrp_adv_inter != 0)
 		carpr.carpr_vrrp_adv_inter = carpr_vrrp_adv_inter;
 
-	if (ifconfig_carp_set_info(lifh, ctx->ifname, &carpr))
-		err(1, "SIOCSVH");
+	if (ifconfig_carp_set_info(lifh, ctx->ifname, &carpr)) {
+		if (ifconfig_err_errtype(lifh) == OTHER)
+			err(1, "%s: %s", __func__,
+			    strerror(ifconfig_err_errno(lifh)));
+		else
+			err(1, "%s: %d", __func__, ifconfig_err_errtype(lifh));
+	}
 }
 
 static void

share/man/man4/carp.4

@@ -24,7 +24,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.Dd April 12, 2024
+.Dd March 11, 2026
 .Dt CARP 4
 .Os
 .Sh NAME
@@ -71,10 +71,7 @@ and
 .Cm advskew
 are put inside CARP advertisements.
 These values can be configured using
-.Xr ifconfig 8 ,
-or through the
-.Dv SIOCSVH
-.Xr ioctl 2 .
+.Xr ifconfig 8 .
 .Pp
 CARP defaults to using multicast messages, but can be configured to unicast
 announcements to peers using the
@@ -88,10 +85,7 @@ and
 Note that TTL verification is disabled if the peer address is not a multicast
 address.
 These values can be configured using
-.Xr ifconfig 8 ,
-or through the
-.Dv SIOCSPEER
-.Xr ioctl 2 .
+.Xr ifconfig 8 .
 .Pp
 .Xr carp 4
 can be configured to use either the non-standard CARP protocol, or VRRPv3 (RFC 5798).

sys/net/if.c

@@ -248,7 +248,6 @@ int	(*carp_master_p)(struct ifaddr *);
 int	(*carp_forus_p)(struct ifnet *ifp, u_char *dhost);
 int	(*carp_output_p)(struct ifnet *ifp, struct mbuf *m,
     const struct sockaddr *sa);
-int	(*carp_ioctl_p)(struct ifreq *, u_long, struct thread *);   
 int	(*carp_attach_p)(struct ifaddr *, int);
 void	(*carp_detach_p)(struct ifaddr *, bool);
 #endif
@@ -2923,15 +2922,6 @@ ifioctl(struct socket *so, u_long cmd, caddr_t data, struct thread *td)
 		error = if_getgroupmembers(req);
 		goto out_noref;
 	}
-#if defined(INET) || defined(INET6)
-	case SIOCSVH:
-	case SIOCGVH:
-		if (carp_ioctl_p == NULL)
-			error = EPROTONOSUPPORT;
-		else
-			error = (*carp_ioctl_p)(ifr, cmd, td);
-		goto out_noref;
-#endif
 	}
 
 	ifp = ifunit_ref(ifr->ifr_name);